CVE-2026-48792
pam_usb: pusb_has_virtual_input_device() silently discards EACCES, disabling remote desktop detection under non-root execution
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.1, src/evdev.c silently ignores EACCES errors when opening /dev/input/event* nodes, causing pusb_has_virtual_input_device() to return 0 (no virtual devices found) even when every open() call failed due to insufficient permissions. The caller in src/local.c cannot distinguish a clean absence of virtual devices from a permission-denied scan, and acts on the false negative by continuing authentication without denying. This vulnerability is fixed in 0.9.1.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
4.4
pam_usb: pusb_has_virtual_input_device() silently discards EACCES, disabling remote desktop detection under non-root execution
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.1, src/evdev.c silently ignores EACCES errors when opening /dev/input/event* nodes, causing pusb_has_virtual_input_device() to return 0 (no virtual devices found) even when every open() call failed due to insufficient permissions. The caller in src/local.c cannot distinguish a clean absence of virtual devices from a permission-denied scan, and acts on the false negative by continuing authentication without denying. This vulnerability is fixed in 0.9.1.
- Record
CVE-2026-48792- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-390, CWE-693
- Updated
- 2026-11-02
EUVDEUVD-2026-32647
4.4
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.1, src/evdev.c silently ignores EACCES errors when opening /dev/input/event* nodes, causing pusb_has_virtual_input_device() to return 0 (no virtual devices found) even when every open() call failed due to insufficient permissions. The caller in src/local.c cannot distinguish a clean absence of virtual devices from a permission-denied scan, and acts on the false negative by continuing authentication without denying. This vulnerability is fixed in 0.9.1.
- Record
EUVD-2026-32647- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
NVD
4.4
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.1, src/evdev.c silently ignores EACCES errors when opening /dev/input/event* nodes, causing pusb_has_virtual_input_device() to return 0 (no virtual devices found) even when every open() call failed due to insufficient permissions. The caller in src/local.c cannot distinguish a clean absence of virtual devices from a permission-denied scan, and acts on the false negative by continuing authentication without denying. This vulnerability is fixed in 0.9.1.
- Record
CVE-2026-48792- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-390, CWE-693
- Updated
- 2026-11-02
OSV
4.4
pam_usb: pusb_has_virtual_input_device() silently discards EACCES, disabling remote desktop detection under non-root execution
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.1, src/evdev.c silently ignores EACCES errors when opening /dev/input/event* nodes, causing pusb_has_virtual_input_device() to return 0 (no virtual devices found) even when every open() call failed due to insufficient permissions. The caller in src/local.c cannot distinguish a clean absence of virtual devices from a permission-denied scan, and acts on the false negative by continuing authentication without denying. This vulnerability is fixed in 0.9.1.
- Record
CVE-2026-48792- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-390, CWE-693
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-48792 is a medium vulnerability (CVSS 4.4) in Mcdope Pam Usb, published May 27, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.13%, the 2nd percentile. No source names a fixed version.